Preparation and application advice

Before any work takes place you must ensure that proper care and attention is given to your safety and those around you.

painting

Wearing appropriate protective clothing is strongly advised, along with rubber gloves and safety glasses or goggles.

If you are unsure check for compatibility, colour and the correct quantity of product that you require at www.seajetpaint.com or from the Seajet catalogue and user guide.

Inspection and Removal
After lifting out and scrubbing off, the hull should be closely examined for damage and fouling attachment.

Grass, weed and loose paint should be removed using a scraper – with the sharp corners on the scraper rounded off with wet or dry paper, to avoid gouging the surface. Larger areas can be dealt with by slurry blasting.

Barnacles may need more thorough treatment, as their cement contains a hormone, which encourages young Barnacle ‘Spat’ to settle nearby. So after scraping, their remains should be wet sanded until they are no longer visible.

Surface preparation
Surfaces to be painted must be clean, dry and free of oil or grease.

Bare surfaces must first be primed with a suitable priming scheme, filling any undulations between coats with an epoxy profiling filler .

Existing anti-foulings don’t usually need any special preparation, but they can be lightly wet sanded, using fresh water, to remove small lumps and ‘blebs’ in the paintwork.

Propellers can be cleaned with an electric drill and wire brush to give a smooth, polished finish. Applying Seajet Peller Clean, for example, will provide subsequent protection for your propeller.

Priming the underwater hull
On bare and filled areas, you should apply touch-ups of primer to ensure good adhesion of the coats to follow.

For hulls where all the existing paint is removed and full coats of the primer system are required, use a high performance epoxy primer, such as Seajet’s 117 or 118 Epoxy Primers.

Be sure to observe the over coating intervals between each coat – Seajet put this information on the tin. Use a brush for smaller areas and a roller for larger areas.

If you don’t know what anti-fouling was last used on your boat, or the condition of the boat is not ideal, apply a good sealer coat, something like Seajet 011 Underwater Primer, for example. You can also check Seajet’s compatibility chart for guidance.

Applying anti-fouling
Generally speaking the performance of anti-foul is directly proportional to the dry film thickness of each coat. Therefore it is important that you apply the recommended quantity as a minimum for a satisfactory result.

Where possible apply your anti-fouling during late morning or early afternoon in calm, dry weather. Avoid the risk of dampness or overnight dew, as this will spoil the results and subsequently affect the performance.

Apply masking tape around the waterline and mask off anodes, shafts and fittings to protect them from unwanted coating.

Before you start put a plastic sheet down to protect the ground and wet the ground with water to prevent dust rising onto your work.

If you are working on a cold day, keep your paint in a warm place or stand the tin in a bucket, part filled with warm water. This will make it easier to apply and give a smoother finish.

Anti-foul can settle, so vigorous stirring with a flat bladed knife is recommended.

Don’t use paint directly from the can; put an appropriate amount in a roller tray and replace the lid. This prevents contamination and premature ageing of the main can contents. Remember to occasionally stir up the tray contents during your work.

Anti-foul is best applied with a mohair roller, but keep a brush handy for those awkward to reach areas. When using a roller, apply the coating in a ‘criss-cross’ pattern, as if you were using a brush. This helps spread the coating evenly. Alternatively, get someone else to follow you with a paint pad. Don’t work the pad backwards or forwards, or try to spread it too thinly.

Apply an extra coat at the leading edges and waterline area, as this is where the boat faces more water- flow. Finally, as soon as the anti-foul feels ‘tacky’ remove the masking tape before the paint dries hard, to give a smoother edge to the paint and one that does not stand proud of the surface.